1. Field of the Invention
The present invention relates to a voltage detecting device, a battery remaining voltage detecting device, a voltage detecting method, a battery remaining voltage detecting method, an electronic timepiece, in particular relates to a technologies of voltage detection of a secondary battery and of a detection of a battery remaining voltage.
2. Prior Art
Lately, there is realized a small-sized electronic timepiece such a type as a wrist watch in which a power generating device such as a solar battery is contained therein to operate without replacing the batter. The above-mentioned electronic timepiece includes a function which charges an electric power generated from the power generating device first to a large capacity capacitor, and then when the electric power is not generated, the time is displayed by the electronic power discharged from the capacitor. Accordingly, it is possible that the timepiece is steadily operated for a long period of time without using a battery. It is then expected that the power generating device is to be contained in many electronic timepieces, considering a time required to replace the battery or a problem caused to trash the battery.
On the other hand, it is obvious that the management of the battery remaining voltage becomes an important issue in the electronic timepiece containing the above-mentioned power generating device.
Then, there is described a technology to manage the battery remaining voltage in the conventional device containing the secondary battery.
[1] The First Conventional Device
As the first conventional device, there is disclosed an electronic device in Japanese Patent Provisional Publication No. 11-64,548.
In the electronic device including the power generating device disclosed in Japanese Patent Provisional Publication No. 11-64548, when the voltage of the secondary power source drops, and the voltage thereof becomes lower than the first detected voltage, a remaining voltage of the power is displayed. Then, when the voltage of the secondary power source further drops and the voltage thereof becomes lower than the second detected voltage, the operations of buzzer and the EL (Electro Luminescence) are inhibited. Then, when the voltage of the secondary power source further drops and the voltage thereof becomes lower than the third detected voltage, a display is inhibited.
As described above, there is disclosed a structure in which a degree of the consumption of the secondary power source is informed to the user, thus preventing a sudden stoppage of the circuit without an advance notice.
[2] The Second Conventional Device
As the second conventional device, there is disclosed an electronic timepiece in Japanese Patent Provisional Publication No. 7-306,275.
In the electronic timepiece disclosed in Japanese Patent Provisional Publication No. 7-306,275, a remaining capacity detecting unit of the secondary battery employs a structure in which when the voltage of the secondary battery successively exceeds a reference voltage corresponding to a prescribed remaining capacity, a battery remaining voltage detecting signal is output so as to renew the battery remaining voltage.
In the electronic device with the power generating device of the first conventional device, since a voltage-capacity property of the secondary power source varied by a rapid charging, a time to practically drive the electronic device varied accordingly, and it was probable that the remaining voltage of the secondary power source was not informed precisely to the user.
In particular, it was probable that in the final stage of the discharging of the secondary power source, i.e., in a region immediate before the drive of the electronic device stopped, the electronic device stopped operating without user""s acknowledgement thereof in spite of the fact that a precise remaining time to enable operation was expected to be informed to the user.
Furthermore, in the electronic timepiece of the second conventional device, although there was no problem even when the battery remaining voltage was renewed according to the reference voltage in case that a charging except a rapid charging was implemented, it was probable that a display of the remaining voltage was hardly renewed, thus causing the user to sense that the charging was not effected well.
Furthermore, when a secondary power source in which an apparent voltage boost generated in a rapid charging operation continued for a long period of time, it was probable that a remaining voltage display was hardly switched.
In addition, it was necessary to provide a timer to set a battery remaining voltage renewal timing which probably enlarged a circuit size.
The object of the present invention is therefore to provide a voltage detecting device and the method thereof for precisely detecting a voltage of a secondary power source in order to precisely and most-timely inform the user of a battery remaining voltage of the secondary power source, a battery remaining voltage detecting device and the method thereof for enabling a precise display of the battery remaining voltage, based on the detected voltage, and an electronic timepiece and electronic device using same.
In accordance with an aspect of the present invention, the present invention provides a voltage detecting device for detecting a voltage of a secondary power source including a detected voltage output unit for outputting a voltage having a correlation to an amount of a stored electricity of said secondary power source as a detected voltage; a rapid charging detecting unit for detecting whether rapid charging to said secondary power source is performed or not; a voltage correction unit for implementing, when said rapid charging is detected, a voltage correction in which a correction voltage corresponding to an apparent boosted voltage generated in said secondary power source due to said rapid charging is superimposed on said detected voltage; and a voltage detection result output unit for outputting a voltage detection result signal, based on said detected voltage or said corrected detected voltage.
Preferably, in the voltage detecting device, said voltage detection result output unit compares said detected voltage or said corrected detected voltage with a predetermined reference voltage to obtain a comparative result and output said result as said voltage detection result signal.
Preferably, in the voltage detecting device, said rapid charging detecting unit includes a charging condition detecting unit for detecting charging to said secondary power source; and a rapid charging condition discrimination unit for discriminating a transition to a rapid charging condition in which said rapid charging is performed, upon detecting that said charging to said secondary power source is remained during a time longer than a predetermined charging reference time.
Preferably, in the voltage detection device, said secondary power source is charged by a power generating device; and said charging condition detecting unit includes a power generation current discriminating unit for discriminating whether a power generation current volume output from said power generating device exceeds a predetermined power generation current volume or not.
Preferably, in the voltage detection device, said secondary power source to is charged by a power generating device; and said charging condition detecting unit includes a stored power voltage discriminating unit for calculating a stored power voltage of said secondary power source based on a power generation current output from said power generating device to discriminates whether said stored power voltage exceeds a predetermined reference stored power voltage or not.
Preferably, in the voltage detection device, said secondary power source is charged by a power generating device; and said charging condition detecting unit includes a comparing unit for comparing a voltage of an output terminal in said power generating device with a prescribed voltage corresponding to a terminal voltage in said secondary power source; and a charging condition discriminating unit for discriminating as being in a charging condition a case in which the voltage of said output terminal exceeds the terminal voltage of said secondary power source, based on a comparative result of said comparing unit.
Preferably, in the voltage detection device, said charging condition detecting unit discriminates whether or not charging to said secondary power source is performed by monitoring a route different from a charging route of said charging. Preferably, in the voltage detection device, said secondary power source is charged by a power generating device; and said rapid charging detecting unit includes a power generating condition detecting unit for detecting a power generating condition in said power generating device; and a rapid charging no condition discriminating unit for discriminating as being in a rapid charging condition upon detecting that said power generating condition is remained during a time longer than a predetermined power generating reference time.
Preferably, in the voltage detection device, said power generating condition detecting unit includes a output voltage comparing unit for comparing an output voltage of said power generating device with a predetermined reference power generating voltage; and a power generating condition discriminating unit for discriminating based on a comparative result of said output voltage comparing unit whether being in a power generating condition or not.
Preferably, in the voltage detection device, said secondary power source is charged by a power generating device; said rapid charging detecting unit includes a charging condition detecting unit for detecting a condition of charging to said secondary power source; a power generating condition detecting unit for detecting a power generating condition of said power generating device; and a rapid charging condition discriminating unit for discriminating as being in a rapid charging condition a case in which detection of said charging is continuously repeated during a time longer than a predetermined charging reference time, or a case in which detection of said power generating condition is continuously repeated during a time longer than a predetermined power generating reference time; and said power generating reference time is set longer than said charging reference time.
Preferably, in the voltage detection device, said power generating condition detecting unit discriminates whether or not a power generation is implemented by monitoring a route a different route from a charging route of said secondary power source.
Preferably, in the voltage detection device, said detected voltage output unit produces a plurality of different detected voltages.
Preferably, in the voltage detection device, said correction voltage is a predetermined offset voltage.
Preferably, in the voltage detection device, said voltage correction unit produces said correction voltage in a manner to correspond to respective said plurality of different detected voltages
Preferably, in the voltage detection device, said voltage detection device further includes a power source kind discriminating unit for discriminating a kind of said secondary power source; and a discriminating result selecting unit for selecting anyone of plurality of voltage detecting result signal corresponding to said plurality of detected voltages, based on a discriminating result of said power source kind discriminating unit to output same.
Preferably, in the voltage detection device, said voltage detection result output unit discriminates a voltage of said secondary power source into a plurality of stages having predetermined voltage ranges; and any one of said correction voltage or said detected voltage output from said detected voltage output unit is set in respective said stages.
Preferably, in the voltage detection device, at least said correction voltage in a group of said correction voltage and said detected voltage output from said detected voltage output unit is set in a manner to correspond to a kind of said secondary power source; said voltage correction unit includes a correction voltage producing unit for producing a plurality of correction voltage corresponding to a kind of said secondary power source; and a correction voltage selecting unit for selecting a correction voltage corresponding to a discriminating result in said power source kind discriminating unit to output same.
Preferably, in the voltage detection device, said correction voltage and said detected voltage output from said detected voltage output unit are respectively set in a manner to correspond to a kind of said secondary power source; said detected voltage output unit includes a detected voltage producing unit for producing a plurality of detected voltages corresponding to a kind of said secondary power source; a detected voltage selecting unit for selecting a detected voltage corresponding to a discriminating result in said power source kind discriminating unit to output same; and said voltage correction unit includes a correction voltage producing unit for producing a plurality of correction voltage corresponding to a kind of said secondary power source; and a correction voltage selecting unit for selecting a correction voltage corresponding to a discriminating result in said power source kind discriminating unit to output same.
Preferably, in the voltage detection device, said power source kind discriminating unit discriminates a kind of said secondary power source, based on a kind designating signal from outside. Preferably, in the voltage detection device, said kind designating signal is input through an external input terminal or input from a memory.
Preferably, in the voltage detection device, said rapid charging condition discriminating unit discriminates a period of time when said rapid charging is kept detected by said rapid charging detecting unit and a period of time when a prescribed waiting time is passed after said rapid charging is not continuously detected as said rapid charging condition.
Preferably, in the voltage detection device, said rapid charging condition discriminating unit discriminates a period of time when said rapid charging is kept detected by said rapid charging detecting unit and a period of time when a prescribed waiting time is passed after said rapid charging stops being detected, as said rapid charging condition.
Preferably, in the voltage detection device, said waiting time is set as a period of time when an apparent voltage boost generated in a rapid charging in said secondary power source becomes almost zero and stable.
Preferably, in the voltage detection device, said voltage detection device further includes: a waiting time storage unit for storing a plurality of waiting times; and a waiting time selecting unit for selecting anyone of waiting times stored in said waiting time storage unit, based on a discriminating result in said power source kind discriminating unit to output same.
Preferably, in the voltage detection device, a measurement of said waiting time is initialized when said rapid charging is detected again before said waiting time is passed.
Preferably, in the voltage detection device, said detected voltage is a voltage after a voltage boost and drop is implemented at a prescribed voltage boost and drop multiplying factor; and said voltage detection device further includes: a discriminating result selecting unit for selecting anyone of a plurality of voltage detection results corresponding to a plurality of said detected voltages, based on said voltage boost and drop multiplying factor to output same.
Preferably, in the voltage detection device, said voltage detection device further includes: a discriminating result selecting unit for selecting anyone of a plurality of voltage detection results corresponding to a plurality of said detected voltages, based on said stage to output same.
Furthermore, the present invention provides a battery remaining capacity detecting device including a voltage detection device described above; and a remaining capacity discriminating unit for discriminating a remaining capacity which is an amount of an electricity which can be output from said secondary power source, based on a voltage detecting result output from said voltage detection device.
The present invention further provides a battery remaining capacity detecting device including a voltage detection device described above; and a remaining capacity discriminating unit for discriminating a remaining capacity which is an amount of an electricity which can be output from said secondary power source, based on a voltage detecting result output from said voltage detection device; and said remaining capacity discriminating unit discriminates a remaining capacity of said secondary power source in such manner that when a predetermined condition is satisfied during a period of time when said waiting time is passed after said rapid charging is not continuously detected as said rapid charging condition, a transition to other conditions except said rapid charging condition is effected.
Preferably, in the battery remaining capacity detecting device, said predetermined condition is a case in which a voltage of said secondary power source is bellow a predetermined lower limit voltage.
Preferably, in the battery remaining capacity detecting device, said predetermined condition is a case in which a remaining capacity of said secondary power source discriminated by said remaining capacity discriminating unit becomes a predetermined remaining capacity.
Preferably, in the battery remaining capacity detecting, said battery remaining capacity detecting device includes a remaining capacity comparing unit for comparing a remaining capacity of said secondary power source immediately before said rapid charging condition is over with a remaining capacity of said secondary power source immediately after transitioning to said non-rapid charging condition, when a transition from said rapid charging condition to said non-rapid charging condition is effected; and said voltage detection result output unit discriminates a voltage of said secondary power source into a plurality of stages having predetermined voltage ranges based on a comparative result in said remaining capacity comparing unit, and when a stage corresponding to a remaining capacity of said secondary power source immediately after transition to said non-rapid charging condition is lower than a stage corresponding to a remaining capacity of said secondary power source immediately before said rapid charging is over, said voltage detection result output unit discriminates said stage corresponding to said remaining capacity of said secondary power source immediately after transition to said non-rapid charging condition as a stage corresponding to a present remaining capacity.
Preferably, in the battery remaining capacity detecting device, said voltage detection result output unit discriminates a voltage of said secondary power source into a plurality of stages having predetermined voltage ranges and said battery remaining capacity detecting device further includes a remaining capacity comparing unit for comparing a stage of a remaining capacity of said secondary power source immediately before said rapid charging condition is over with a stage of a remaining capacity of said secondary power source immediately after transitioning to said non-rapid charging condition, when a transition from said rapid charging condition to said non-rapid charging condition is effected; and a rank-up inhibiting control unit for inhibiting rank-up of said stage based on a comparative result in said remaining capacity comparing unit in a way that until a predetermined rank-up inhibiting cancellation condition is satisfied, a rank-up of stage is inhibited when a stage corresponding to a remaining capacity of said secondary power source immediately after transition to said non-rapid charging condition is higher than a stage corresponding to a remaining capacity of said secondary power source immediately before said rapid charging is over.
Preferably, in the battery remaining capacity detecting device, said rapid charging detecting unit includes a charging condition detecting unit for detecting a charging condition to said secondary power source; and said rank-up inhibiting cancellation condition is a case in which a charging condition is detected by said charging detecting unit.
Preferably, in the battery remaining capacity detecting, said battery remaining capacity detecting device includes a charging cut-off unit for forcefully cutting off a charging of said secondary power source, when detecting a voltage having a correlation to a remaining capacity of said secondary power source.
The present invention further provides a method for detecting a voltage of a secondary power source comprising steps of outputting a voltage having correlation to a remaining capacity of said secondary power source as a detected voltage; detecting whether a rapid charging is effected in said secondary power source or not; implementing, when said rapid charging is detected, a voltage correction in which a correction voltage corresponding to an apparent boosted voltage generated in said secondary power source due to said rapid charging is superimposed on said detected voltage; and outputting a voltage detection resultant signal, based on said detected voltage or said corrected detected voltage.
Preferably, in the method, said method further comprises a step of comparing the detection object voltage obtained according to the method described above with a predetermined reference voltage to discriminate a remaining capacity of said secondary power source.
The present invention further provides an electronic timepiece including a secondary power source supplying a power source for driving; a time keeping unit driven by said secondary power source; and a voltage detecting device described above.
The present invention further provides an electronic timepiece including a secondary power source supplying a power source for driving; a time keeping unit driven by said secondary power source; and a battery remaining amount detecting device described above.
The present invention further provides an electronic device including a secondary power source supplying a power source for driving; a driven unit driven by said secondary power source; and a voltage detecting device described above.
The present invention further provides an electronic device including a secondary power source supplying a power source for driving; a driven unit driven by said secondary power source; and a battery remaining amount detecting device described above.